1. Field of the Invention
The present invention concerns a process and a device for controlling and monitoring of a traffic control system, and more particularly, to a process and device for controlling and monitoring railcars and rails therefor.
2. Discussion of Background Information
Various procedures are used in signal boxes to assign travel routes for railroad traffic. Electronic signal boxes, working in accordance with the principle of secured charts, have a memory in which all selectable routes are recorded. German Patent Application No. DE-AS 10 30 383 (see also DE-PS 35 35 785 C2, column 4, lines 38-47) describes an electronic signal box in which the target loads of all travel route segments to be included in the individual travel routes are stored in a table provided in a memory. The signal orders for the individual travel route segments are derived from the deviations between target and actual loads. This, however, entails a large memory requirement, which increases substantially with the size of the system to be controlled. At larger train stations, more than 50,000 start/finish combinations can be programmed under certain circumstances. In this process, in order to attain the necessary degree of safety, it is necessary to ensure that all data relating to the selectively programmable travel routes have been correctly chosen and stored.
In order to guarantee the greatest possible degree of safety, however, electronic route interlocking stations are primarily in use today, such as are described for example in German Patent No. DE-PS 32 32 308. In the course of the search for travel routes, data words for the computers marked as start and end are entered into the networked multi-computer system linked in accordance with the track diagram; during this process, data words are deposited for a great many switches, a large portion of which will not be needed later. The unnecessary storing and deleting of data words in this electronic signal box leads to "superfluous" processing procedures, which assume unjustifiable proportions, particularly in complex systems.
To reduce costs, in a process known from German Patent No. DE-PS 35 35 785 C2, target-group information is stored in track segments located near tapering switch points, which simplifies the search for travel routes. However, the correct determination and decentralized storage of information in the appropriate memory units entails a corresponding cost.
German Patent Publication No. DE 43 20 574 A1 describes a simplified monitoring of a system controlled by an electronic signal box operating according to the track diagram principle. Herein, individual partial controls are assigned to several track elements at the same time, in order to become operative for them jointly with regard to clear reports and releases. By this means, operational malfunctions are avoided which could otherwise arise as a result of unexpectedly occurring, differing work conditions of the individual track segments. Even this advantageous solution, however, is not suitable for bringing about a greater simplification of the electronic signal box.
The observation of the required safety standards is also of importance. In DE-PS 32 32 308, any failures of the components, which can lead to a change in transferred data, are identified through the transfer and comparison of exclusive-OR data words. This, however, leads to additional cost, without a comprehensive safety test being performed thereby.
It is known from German Patent Publication No. DE-AS 24 02 875 that protection from processing errors can be obtained when all important commands pertaining to safety are processed through two independent ways at practically double cost, where, in operation with only one computer, the double processing of commands is performed with two different programs and an interposed command verification program, through which the processed orders are compared.
Further, European Patent No. EP 0 683 082 A1 describes a device in which the operator of a control system is almost completely freed of monitoring tasks. Here, previously programmed combinations of switch conditions are read out by an indicating device and tested for compatibility with rules of logic stored in a data processing system. These rules of logic are to be prepared during the designing of a signal box and tested for accuracy. In order to guarantee comprehensive safety, error-free rules of logic must be provided at great cost for all switch conditions which might arise.